﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

/// <summary>
/// 重载运算符：
/// https://www.runoob.com/csharp/csharp-operator-overloading.html
/// </summary>
namespace _07_operator_overloading
{
    class Program
    {
        static void Main(string[] args)
        {
            Box Box1 = new Box();          // 声明 Box1，类型为 Box
            Box Box2 = new Box();          // 声明 Box2，类型为 Box
            Box Box3 = new Box();          // 声明 Box3，类型为 Box
            Box Box4 = new Box();
            double volume = 0.0;   // 体积

            // Box1 详述
            Box1.setLength(6.0);
            Box1.setBreadth(7.0);
            Box1.setHeight(5.0);

            // Box2 详述
            Box2.setLength(12.0);
            Box2.setBreadth(13.0);
            Box2.setHeight(10.0);

            // 使用重载的 ToString() 显示两个盒子
            Console.WriteLine("Box1： {0}", Box1.ToString());
            Console.WriteLine("Box2： {0}", Box2.ToString());

            // Box1 的体积
            volume = Box1.getVolume();
            Console.WriteLine("Box1 的体积： {0}", volume);

            // Box2 的体积
            volume = Box2.getVolume();
            Console.WriteLine("Box2 的体积： {0}", volume);

            // 把两个对象相加
            Box3 = Box1 + Box2;
            Console.WriteLine("Box3： {0}", Box3.ToString());
            // Box3 的体积
            volume = Box3.getVolume();
            Console.WriteLine("Box3 的体积： {0}", volume);

            //comparing the boxes
            if (Box1 > Box2)
                Console.WriteLine("Box1 大于 Box2");
            else
                Console.WriteLine("Box1 不大于 Box2");
            if (Box1 < Box2)
                Console.WriteLine("Box1 小于 Box2");
            else
                Console.WriteLine("Box1 不小于 Box2");
            if (Box1 >= Box2)
                Console.WriteLine("Box1 大于等于 Box2");
            else
                Console.WriteLine("Box1 不大于等于 Box2");
            if (Box1 <= Box2)
                Console.WriteLine("Box1 小于等于 Box2");
            else
                Console.WriteLine("Box1 不小于等于 Box2");
            if (Box1 != Box2)
                Console.WriteLine("Box1 不等于 Box2");
            else
                Console.WriteLine("Box1 等于 Box2");
            Box4 = Box3;
            if (Box3 == Box4)
                Console.WriteLine("Box3 等于 Box4");
            else
                Console.WriteLine("Box3 不等于 Box4");

            Console.ReadKey();
        }

        class Box
        {
            private double length;      // 长度
            private double breadth;     // 宽度
            private double height;      // 高度

            public double getVolume()
            {
                return length * breadth * height;
            }
            public void setLength(double len)
            {
                length = len;
            }

            public void setBreadth(double bre)
            {
                breadth = bre;
            }

            public void setHeight(double hei)
            {
                height = hei;
            }
            // 重载 + 运算符来把两个 Box 对象相加
            public static Box operator +(Box b, Box c)
            {
                Box box = new Box();
                box.length = b.length + c.length;
                box.breadth = b.breadth + c.breadth;
                box.height = b.height + c.height;
                return box;
            }

            public static bool operator ==(Box lhs, Box rhs)
            {
                bool status = false;
                if (lhs.length == rhs.length && lhs.height == rhs.height
                   && lhs.breadth == rhs.breadth)
                {
                    status = true;
                }
                return status;
            }
            public static bool operator !=(Box lhs, Box rhs)
            {
                bool status = false;
                if (lhs.length != rhs.length || lhs.height != rhs.height
                    || lhs.breadth != rhs.breadth)
                {
                    status = true;
                }
                return status;
            }
            public static bool operator <(Box lhs, Box rhs)
            {
                bool status = false;
                if (lhs.length < rhs.length && lhs.height
                    < rhs.height && lhs.breadth < rhs.breadth)
                {
                    status = true;
                }
                return status;
            }

            public static bool operator >(Box lhs, Box rhs)
            {
                bool status = false;
                if (lhs.length > rhs.length && lhs.height
                    > rhs.height && lhs.breadth > rhs.breadth)
                {
                    status = true;
                }
                return status;
            }

            public static bool operator <=(Box lhs, Box rhs)
            {
                bool status = false;
                if (lhs.length <= rhs.length && lhs.height
                    <= rhs.height && lhs.breadth <= rhs.breadth)
                {
                    status = true;
                }
                return status;
            }

            public static bool operator >=(Box lhs, Box rhs)
            {
                bool status = false;
                if (lhs.length >= rhs.length && lhs.height
                   >= rhs.height && lhs.breadth >= rhs.breadth)
                {
                    status = true;
                }
                return status;
            }
            public override string ToString()
            {
                return String.Format("({0}, {1}, {2})", length, breadth, height);
            }

        }
    }
}
